The present invention generally relates to a smoke screen shell. More particularly, the present invention relates to a smoke screen shell for discharging a rapidly burning component or decoy charge that produces a spontaneous fog and a slowly burning component or camouflage charge that produces a lasting fog. The present smoke screen shell has an ignition system for igniting an ejection charge, the decoy charge and the camouflage charge, whereby the decoy charge takes effect in the air before the camouflage charge after the initiation of the smoke screen shell, and a collocation of the spontaneous fog and the lasting fog essentially occurs in the target.
Smoke screening is a tactical and operational measure that is often employed where there is a need for an infrared-masking fog, such as for the protection of a tank or other vehicle. This is realizable by providing two pyrotechnic components. A decoy charge is reacted first for an immediate masking of the vehicle to be protected, creating a spontaneous fog. A camouflage charge is also reacted to deploy a longer-lasting fog. The decoy charge must take effect as soon as possible and the camouflage charge must take effect with delayed timing within the proximity of the decoy charge. Thus the smoke screen shell must be adapted to ignite the two components in a chronologically delayed fashion for effecting the functional sequence of each component. Furthermore, the smoke screen shell must be configured to project the components at a desired spatial proximity from each other.
DE 41 25 355 C1, for example, discloses a smoke screen shell of the type described above, wherein a grappling line system makes it possible for the decoy charge land with the camouflage charge. After being fired from an ejector member, the decoy and camouflage charges remain tethered to the firing location via a grappling line whose length corresponds to the desired firing distance. The line is pulled taut when the desired firing distance has been reached, thereby mechanically igniting a propellant charge, resulting in a deployment of the decoy charge and subsequent deployment of the camouflage charge after well-defined delay time. However, a grappling line system is disadvantageous because it is not redeployable due to lack of space, particularly when configured for small caliber munitions such as 76 mm or 66 mm.
Both DE 30 35 799 C2 and Norwegian Letters Patent R 8000 disclose two-component smoke screen shells wherein a decoy charge is fired from a launcher tube chronologically before a camouflage charge, and the decoy charge is deployed closer to the firing location than the camouflage charge, in spatial terms, so that no collocation of the spontaneous fog and of the lasting fog occurs. The smoke screen shells of these two publications achieve enhanced functional reliability when used in moist or damp conditions.
Furthermore, DE 38 44 300 A1 discloses a single-component smoke screen shell which has a elongated tube that can be inserted into an ejector canister and from which active material can be fired. The elongated tube thus forms a secondary ejector canister, preventing contamination and damage to the actual ejector. The elongated tube also allows greater quantities of active material to be fired in the same range, and the power of recoil is reduced due to the internal ballistic properties of the elongated tube.